The present invention relates to an operation microscope, particularly for ophthalmological microsurgery.
It is necessary in certain procedures of ophthalmological surgery for the patient to bring the visual axis of his eye as closely as possible into the direction of observation (instrument central axis) of the operation microscope and to hold it there for a relatively long time. My U.S. Pat. No. 4,478,799 discloses several alternatives for meeting this need, with fixation-target projection through the single main objective of a binocular microscope.
In certain other ophthalmological procedures, it is desired to mark the optical zone of the cornea whereby it can be known that subsequent operative manipulations can be accurately referenced to the optical zone. Such marking may illustratively take the form of using a ring tool to temporarily impress an indented circular "mark" on the anterior surface of the cornea. The fixation devices of my said patent are unequal to this task, for binocular viewing, largely because there is no means whereby the physician can know that his indenting tool is centered on the visual axis of the eye under observation.